Truck-mounted material handling device



Nov. 5, 1957 c. J. WESTLING TRUCK-MOUNTED MATERIAL HANDLING DEVICE 6Sheets-Sheet 1 Filed May 8. 1955 INVENTOR.

CARL J. WESTLJNG yam/9 HIS ATTORNEY Nov. 5, 1957 c. J. WESTLINGTRUCK-MOUNTED MATERIAL HANDLING DEVICE 6 Sheets-Sheet 2 Filed May 8.1955 INVENTOR.

CARL. J. WESTLING W? 9 HIS ATTORNEY Nov. 5, 1957 c. J. WESTLINGTRUCK-MOUNTED MATERIAL HANDLING DEVICE 6 Sheets-Sheet 3 Filed May 8,195a JNVENTOR.

CARL J. WESTLING M %0v1w HIS ATTORNEY Nov. 5, 1957 c. J. WESTLlNG2,811,881

TRUCK-MOUNTED MATERIAL HANDLING DEVICE Filed May 8, 1953 6 Sheets-Sheet4 INVENTOR.

CARL J. WESTLING W jZMQA V w HIS ATTORNEY! Nov. 5, 1957 c. J. WESTLINGmum-Momma MATERIAL HANDLING DEVICE 6 Sheets-Sheet 6 Filed May 8. 1953INVENTOR.

CARL WESTLNG BWZMM/W HIS ATTORNEY United States Patent TRUCK-MOUNTEDMATERIAL HANDLING DEVICE Carl J. Westling, Pittsburgh, Pa., assignor toVulcan Research Corporation, Pittsburgh, Pa., a corporation ofPennsylvania Application May 8, 1953, Serial No. 353,826 4 Claims. (Cl.78-96) This invention relates to a truck-mounted material handlingdevice of general utility but especially useful for manipulating workfor performance on the work of operations such, for example, as forging,for charging work into and withdrawing the same from heating furnacesand for similar uses in which heavy and usually hot masses are beingmanipulated.

Problems ditheult of solution are presented in the efficient handling ofheavy masses such as steel billets, particularly when the masses are atforging temperature. The masses during handling must be disposed at asuffieient distance from the operator so that the operator will not beovercome by their heat; also when the mani pulator is used for chargingthe masses into and withdrawing the same from heating furnaces the peelor supporting arm must be of substantial length. It is not easy tosupport and manipulate a heavy mass at the tongs end of a long peelwithout considerably elongating the manipulator in the direction of thelength of the peel away from the mass. Also vexing problems arise inprotecting portions of the manipulator removed from the tongs from theshocks which are imparted to the peel during forging and otheroperations upon work carried by the peel.

I have devised a truck-mounted material handling device comprising aself-propelled wheeled truck of the type used for lifting andtransporting articles which has load-lifting mechanism and acounterweighted load-carrying arm carried by the load-lifting mechanism.A generally horizontal pivot is preferably carried by the loadliftingmechanism and the counterweighted load-carrying arm is preferablycarried by the load-lifting mechanism for pivotal movement about saidpivot with the center of gravity of the arm being disposed somewhatinwardly of said pivot (i. e., away from the load) so that when the armis carrying a load the center of gravity of the combined arm and loadwill be in the proximity of said pivot. However, advantages of myinvention are obtainable even though the load-carrying arm is notpivoted to the load-lifting mechanism but instead is rigidly fastenedthereto since, because the arm projects a considerable distance from theload-lifting mechanism, its action is similar to a turning movementabout a pivot; thus my invention in its broadest aspect may include atruck-mounted material handling device in which the load-carrying arm orpeel is rigidly fastened to the load-lifting mechanism although furtherimportant advantages are realized by pivoting the load-carrying arm tothe load-lifting mechanism as will later appear.

The length of the load-carrying arm or peel will be determined for anyparticular material handling device or manipulator not merely by thereach required to serve a furnace or a hammer or press but, moreimportantly, so as to obtain the proper balance of mass so that when aload carried by the peel is subjected to the impact of a forging hammerthe shock effects will be largely compensated for and not transmittedinto the carrying chassis which in a truck of the type employed may notbe con- 2,811,881 Patented Nov. 5, 1957 structed to withstand heavyshock loads. To accomplish this result the center of gravity of thecombined peel and load when the manipulator is in use handling workshould be at or very close to the forward point of support of the peel.The point of inflection in the moment diagram will fall near the forwardpoint of support and shock effects are thus largely cancelled out atthat point. Consequently, the center of gravity of the unloaded peelshould be somewhat to the rear of the forward point of support of thepeel since the application of a load to the end of the peel moves thecenter of gravity of the loaded peel forwardly or toward the load.

I preferably provide resilient stability means extending between andconnected with the loadlifting mechanism and the load-carrying arm forresiliently maintaining the arm in substantially predeterminedorientation. The load-carrying arm may be provided with counterweightmeans carried by the arm for shifting the center of gravity of the armlongitudinally of the arm to adapt the arm for different load carryingrequirements. Such counterweight means may comprise a counterweightshiftable along the arm or a series of weights which may be applied andremoved at will.

More specifically, I have devised a truck-mounted material handlingdevice in which a self-propelled wheeled truck of the type used forlifting and transporting articles which has load-lifting mechanism isemployed as the supporting and maneuvering element in which I havesolved the existing problems so that heavy hot masses can be handled atthe end of an elongated arm or peel without greatly extending the lengthof the device. I also minimize the shocks imparted to the truck whenwork carried by the device or manipulator is being forged. My device,which may for convenience be termed a lift truck manipulator, has anumber of novel features from which advantages are realized as willappear below.

I preferably provide resilient stabilizing means extenda generallyupright guideway carried by the truck, a crosshead guided by theguideway, means for moving the crosshead to selected positions in theguideway, a peel pivotally carried by the crosshead and resilient meansmaintaining the pee] in approximately predetermined orientation butpermitting pivotal movement of the peel relatively to the crosshead whenshocks are imparted to the peel. I preferably provide connectionsbetween the guideway and the truck whereby the guideway is carried bythe truck but movable to positions at selected angles to the horizontal.In a preferred structure the guideway is pivotally connected to thetruck by a generally horizontal pivot and means are provided for movingthe guideway about the pivot to position it at selected angles to thehorizontal.

The peel preferably projects from the crosshead generally horizontallyin one direction and counterbalancing means are preferably providedwhich are connected with the peel and project from the crossheadgenerally horizontally in the direction opposite that in which the peelprojects. The peel preferably projects from the crosshead generallyhorizontally away from the truck and the counterbalancing meanspreferably lie generally alongside the truck. I prefer to employ twocounterbalancing elements connected with the peel and projecting fromthe crosshead generally horizontally in the direction opposite that inwhich the peel projects and lying generally alongside the truck atopposite sides thereof.

The peel is preferably pivotally carried by the crosshead through agenerally horizontal pivot and projects from the crosshead generallyhorizontally away from the truck and a transversely extending member ispreferably provided which is connected with the peel and projectslaterally therefrom in both directions, two counterbalancing elementsbeing connected respectively to the oppositely projecting portions ofthe transversely extending member and projecting generally horizontallyin the direction opposite that in which the peel projects and lyinggenerally alongside the truck at opposite sides thereof. Resilient meansare preferably provided maintaining the peel in approximatelypredetermined angular position relatively to the horizontal butpermitting pivotal movement of the peel relatively to the crosshead whenshocks are imparted to the peel.

A peel operating motor is preferably carried by the peel and flexibleconnections to the motor are provided for operating the same. The motormay be an electric motor, an oil motor or other type of motor suitablefor operating the peel, the motor in the form shown being used forturning the peel about its axis.

The crosshead may be generally vertically elongated and the peel may bepivotally carried by the crosshead at the lower portion of the crossheadand may project generally horizontally from the crosshead, in which casethe resilient means preferably extend from the upper portion of thecrosshead to a portion of the peel substantially spaced from thecrosshead maintaining the peel in approximately predetermined angularposition relatively to the horizontal but permitting pivotal movement ofthe peel relatively to the crosshead when shocks are imparted to thepeel.

The peel operating motor may be mounted atop the peel and the resilientmeans may have portions at opposite sides of the motor. In a preferredstructure the resilient means may comprise a yoke having its crosselement connected with the peel at a portion of the peel substantiallyspaced from the crosshead and having its side elements extendinggenerally upwardly and toward the upper portion of the crosshead andresilient connections between the side elements and the upper portion ofthe crosshead. The peel preferably carries tongs at the outer endthereof in which case means are provided for operating the tongs to gripand release work.

To assist in absorbing shocks imparted to the peel resilient connectionsmay be provided between the crosshead and the means for moving thecrosshead in the guideway and/or between the peel and the crossheadand/or between the guideway and the means for moving the guideway aboutits pivotal connection with the truck. Such means may be employedindividually or in various combinations depending upon the particularwork to be done and one or more of them may be utilized with theresilient means maintaining the peel in approximately predeterminedorientation but permitting pivotal movement of the peel relatively tothe crosshead when shocks are imparted to the peel.

Other details, objects and advantages of the invention will becomeapparent as the following description of certain present preferredembodiments thereof proceeds.

In the accompanying drawings I have shown certain present preferredembodiments of the invention in which Figure l is a side elevationalview of a lift truck manipulator;

Figure 2 is a fragmentary top plan view of the lift truck manipulatorshown in Figure I;

Figure 3 is a front elevational view of the lift truck manipulator shownin Figures 1 and 2;

Figure 4 is a fragmentary view partly in cross section of a portion ofthe structure shown in Figure I;

Figure 5 is a fragmentary cross-sectional view taken on the line V-V ofFigure 2;

Figure 6 is a fragmentary vertical central cross-sectional view toenlarged scale through a portion of the manipulator;

Figure 7 is a fragmentary view to enlarged scale partly in elevation andpartly in vertical transverse cross-section showing a modified form ofconnection between the crosshead and the means for moving the crossheadin the guideway;

Figure 8 is a fragmentary vertical longitudinal crosssectional view toenlarged scale showing a modified form of connection between thecrosshead and the peel;

Figure 9 is a fragmentary side elevational view to enlarged scaleshowing a modified form of connection between the guidcway and the meansfor moving the guideway to turn it about its pivotal connection with thetruck; and

Figure 10 is a fragmentary vertical cross-sectional view taken on theline X-X of Figure 9.

Referring now more particularly to the drawings, the manipulator showntherein comprises a lift truck designated generally by reference numeral2 comprising a body 3 mounted for movement from place to place upon afloor or track on wheels 4 shown as being rubber tired. Normally themanipulator operates upon a floor in which case the wheels 4 preferablyhave rubber tires as shown although the manipulator may be used upon atrack in which case the wheels 4 may be flanged metal car wheels. In thestructure shown there are two front wheels 4 mounted upon an axle 5which may be driven to move the manipulator from place to place and asingle rear wheel 4 mounted for turning movement in a generallyhorizontal plane to steer the truck. Steering gear which may beconventional is provided, the gear being operated through a shaft 6provided with a steering wheel 7. The operator sits in a seat 8 mountedon the body 3. In front of the operators seat and the steering wheel isa tubular steel frame 9 having upwardly extending and somewhatrearwardly inclined side members 10 and cross members IL A heat shield12 is mounted on the frame 9 to protect the operator from the heat ofthe work being handled by the manipulator or the heat of a furnace intowhich the work is charged or from which it is withdrawn. At each side ofthe drivers seat is a tubular metal frame 13 swingably mounted on themember 10 at that side of the body at 14 so that it can be swungoutwardly to permit the operator or mechanic to get at or service themechanism of the lift truck. Wire mesh 15 mounted in an inner frame 17is mounted in each of the frames 13. A latch 18 is provided for latchingeach of the frames 13 in closed position. The side frames 13 whenmounted as shown on the inclined side members 10 tend to swing bygravity to closed position. The side frames constitute guards to protectthe operator from the rearwardly extending counterweight arms presentlyto be described.

Mounted on the front axle 5 for limited turning move ment about the axisof the front axle is a frame 19. The frame 19 has at its bottomprojecting portions 81 having bearing upon the axle 5 and opposed sidemembers 82 connected by a cross member 83. The side members 82 are inthe form of inwardly open channels and cooperatively form a guideway inwhich the manipulator crosshead, presently to be described, operates.The frame 19 has pivotally connected therewith at each side thereof at84 a piston rod 85 connected with a piston in a cylinder 86 pivoted tothe body 3 at 87 whereby the frame 19 may be moved through a small angleabout the axis of the axle 5 to alter the inclination relatively to thehorizontal of the manipulator crosshead and hence of the peel presentlyto be described which is carried by the cross head. The frame 19 isshown in solid lines in Figure l in substantially vertically uprightposition and in chain lines in an angular position a few degrees removedfrom the solid line position and to the left. The frame 19 may likewisebe turned to the right from the solid line position through a smallangle by operation of the pistons in the cylinders 86.

The crosshead of the manipulator, which is designated generally byreference numeral 126, comprises elongated generally vertical sidemembers 88 connected at the top by a transverse member 89 and having atthe bottom members 90 to which is pivotally connected at 91 a crossmember 96. Thus the crosshead 126 is generally vertically elongated.Mounted centrally at the bottom of the frame 19 is a cylinder 93 inwhich operates a piston having a piston rod 94 connected with thetransverse member 89 of the crosshead through members 95. By operationof the piston in the cylinder 93 the crosshead is moved up and down inthe guideway formed by the channels 82 and may be moved to selectedpositions in the guideway. The crosshead carries rollers 82a whichoperate in the channels 82 as clearly shown in Figure 2.

From the ends of the cross member 96 depend generally vertical members97 rigidly connected with the cross member. Connected with and extendingrearwardly from the cross member 96 and the members 97 at both sides ofthe body are arms 98 respectively carrying at their rearward endscounterweights 99. The purpose of the counterweights is tocounterbalance the mass of the portion of the manipulator structurewhich projects forwardly from the pivot 91.

The mass of the portion of the manipulator structure which projectsforwardly from the pivot 91 is counterbalanced for several reasons. Lifttrucks are rated as to their lift capacity for specific loads which varydownwardly as the horizontal distance of the load from the verticaltrack of the lift truck increases. The maximum load capacity is attainedwhen the load is close to the track. Consequently it is of considerableimportance to design the manipulator structure so that the center ofgravity of the manipulator mechanism is at or close to the verticaltrack. Moreover, it is important to obtain proper distribution of massin the peel with respect to its support in order to minimize or cancelout the shocks to which the manipulator is subjected when work held bythe manipulator is being forged. Such shocks if not properly compensatedfor could result in rapid deterioration of the lift truck andmanipulator mechanism.

Projecting forwardly and inwardly from the ends of the cross member 96are inclined members 100 joined at their forward ends by a transversemember 101. The member 101 carries a pair of upwardly projecting lugs102 through which passes the cross element 103 of a yoke 104 havingopposed generally upwardly and rearwardly inclined side members 105. Abar 106 extends transversely of the yoke 104 generally parallel to thecross element 103, each of the side members 105 of the 'oke passingthrough the bar 106. The upper end of each of the members 105 isthreaded and each such member has a not 107 thereon below the bar 106.Each of.

the members 105 has a coil spring 108 disposed thereabout above the bar106, a out 109 and a washer 110 being applied above the spring.

A rod 111 is pivotally connected with the upper portion of the crossheadat 112 and extends downwardly and toward the right viewing Figure l andpasses through the bar 106, a nut 113 being threaded onto the lower endof the rod 111 below the bar 106. A coil spring 114 sur rounds the rod111 above the bar 106 and a nut 115 and washer 116 are applied to therod 111 above the spring 114.

Thus the crosshead and hence the peel carried thereby presently to bedescribed is maintained in approximately predetermined orientation butis turnable about the axis of the pivot 91 when subjected to shock aswhen work being held by the peel is being forged. Clockwise turning ofthe crosshead about the axis of the pivot 91 viewing Figure l isresiliently resisted by the springs 108 on the members 105 whilecounterclockwise turning of the manipulator head is resiliently resistedby the spring 114 on the rod 111. Thus the shocks imparted to the peelare considerably reduced in intensity before they are transmitted to thetruck. Since both the peel and the structure 100, 101, 102 are carriedby and rigidly connected with the cross member 96 the yoke 104 isconnected with and in effect acts on the peel; in other words, thestructure 96, 100, 101, 102 may be regarded as part of the peel.

The cross member 96 has a web in the form of a plate 16 to which iswelded at 20 a ring 21 into which bolts 22 are threaded. Any appropriatenumber of such bolts may be employed, it being by preference to useeight bolts equally spaced about the ring 21. The ring 21 has an inneraxial annular flange 23.

The principal element of the support for the peel carrier and peeloperator is a cylinder 24 having a flange 25 welded to one end at 26.The flange 25 is provided with bolt holes 27 to receive the bolts 22 andnuts 28 are applied to the bolts to the right of the flange 25 viewingFigure 6 and are drawn up tightly against the flange whereby tounitarily attach the cylinder 24 to the ring 21 and hence to the plate16. Adjacent its left-hand end viewing Figure 6 the cylinder 24 iscounterbored as shown at 29 and the end of the cylinder telescopes overthe flange 23 as shown. The counterbore 29 provides a radial annularshoulder 30 within the cylinder 24. A hearing race 31 is disposedbetween the shoulder 30 and the end face of the flange 23 as shown inFigure 6. The parts are proportioned so that when the nuts 28 aretightened the bearing race 31 is maintained firmly in place and heldagainst axial movement. The cylinder 24 has a bore 32 which is tappedand receives a lubrication fitting 33 through which lubricant may beintroduced to lubricate the hearing within the bearing race 31.

The peel carrier. which is designated generally by reference numeral 34.comprises a cylindrical end portion 35 which is mounted for rotation ina bearing 36 disposed within the race 31. A plate 37 is bolted to theend of the peel carrier by bolts 33, there preferably being three suchbolts having their axes arranged as the apices of an equilateraltriangle equidistant from the axis of the peel carrier. Shims 39 may beprovided between the end face of the peel carrier 34 and the plate 37 ifneeded. The bearing 36 not only provides for mounting of the peelcarrier for rotation within the cylinder 24 but also maintains the peelcarrier against axial movement. The bolts 38 are rendered accessible byremoval of the cylinder 24 from the plate 16. The bearing is confinedbetween a shoulder 40 of the peel carrier and the plate 37.

The outer extremity of the cylinder 24 is shown at 41. Slightly to theright of that extremity the peel carrier 34 has an annular radial flange42. At the outer extremity of the flange 42 is an annular axial flange43 which extends toward the left from the flange 42 viewing Figure 6.The flange 43 is provided at its inner surface with a bearing rollerreceiving cavity 44 in which are disposed bearing rollers 45 hearingagainst the outer face of the cylinder 24 at its right-hand extremity. Asealing ring 46 is provided to prevent increase of foreign matter intothe bearing comprising the rollers 45. Thus the peel carrier 34 ismounted for rotation within the cylinder 24 by the bearings 36 and 45and is maintained against axial movement by the bearing 36. For turningthe peel carrier 34 it is provided with a sprocket 47 which is welded tothe exterior surface of the flange 43 as shown at 48. A sprocket chain49 is trained about the sprocket 47 and about a driving sprocket 117presently to be described turning of the driving sprocket turning thepeel carrier 34.

The peel carrier 34 has a cylindrical portion 50 whose outside diameteris substantially less than the inside diamcter of the opposed portion ofthe cylinder 24. Ports 51 extend through the peel carrier 34 near theends of the portion 50. Sealing rings 52 seal the peel carrier 34 to thecylinder 24 to the left of the left-hand ports 51 and to the right ofthe right-hand ports 51 viewing Fig ure 6. A double sealing ring 53seals the peel carrier 34 to the cylinder 24 approximately midwaybetween the sealing rings 52. Spacing rings 54 are disposed between thesealing ring 53 and the respective sealing rings 52. The right-handextremity of the right-hand sealing ring 52 viewing Figure 6 abutsagainst the flange 42. A nut 55 is threaded onto an externally threadedportion 56 of the peel carrier 34 and is turned up against the lefthandface of the left-hand sealing ring 52. A lock nut 56 holds the nut 55 inposition. Thus the sealing rings 52 and 53 and the spacing rings 54 aremaintained in position on the peel carrier 34 and turn with the peelcarrier when the peel carrier is turned within the cylinder 24. Thespacing rings 54 have passages therethrough communicating respectivelywith the corresponding ports 51. Also, fluid passages 57 are providedthrough the cylinder 24 communicating with the respective passagesthrough the spacing rings 54 and thence with the corresponding ports 51.By supplying fluid under pressure through one or the other of thepassages 57 the peel operator now to be described may be operated withinthe peel carrier 34. When fluid under pressure is admitted through oneor the other of the passages 57 the resultant axial thrust isself-contained within the peel carrier assembly and therefore the thrustdoes not affect or resist the turning movement of the peel.

The peel operator is designated generally by reference numeral 58 andhas a portion disposed within the peel carrier 34 and a portionprojecting to the right therefrom as shown in Figure 6. The peeloperator 58 comprises a piston 59 operable within the cylindrical borein the portion 59 of the peel carrier. A rod 60 is connected with thepiston 59 and extends to the right therefrom viewing Figure 6.

I provide a sealing unit, designated generally by reference numeral 61,adapted to be applied to the righthand end of the peel carrier 34viewing Figure 6 to seal the rod 60 thereto while providing for axialmovement of the peel operator. A sealing unit comprises a cup 62 snuglyreceivable in the right-hand end of the peel carrier 34 and adapted tobe threadedly connected therewith through complementary threads 63. Thecup 62 has an annular recess 64 receiving an O-ring 65 for sealing thecup to the interior of the peel carrier 34. The transverse wall 66 ofthe cup has therethrough a bore 67 to receive the rod 60, and a packingring 63 is disposed within the cup to seal against the rod. The packingring 68 has a reentrant portion 69 at its outer end to receive a hooklike tool for withdrawing it. The packing ring 68 is pressed into placeby a pressure ring 70 threaded into the cup 62 by complementary threads71. A sea] 72 is provided to keep foreign matter out of the peel carrierwhen the rod 60 moves toward the left viewing Figure 6.

The packing ring 68 may be changed without removing the cup 62 or theentire sealing assembly may be removed if desired. Wrench engaging lugs73 are provided on the cup 62 and similar lugs 74 are provided on thepressure ring 70.

The peel proper is designated 75 and comprises a tubular member to whichis welded at 76 a flange 77 through which the peel is bolted to the peelcarrier 34 by bolts 78 threaded into the flange 42. Nuts 79 are appliedto the bolts 78. A passage 80 is provided through which any fluidleaking past the sealing unit 61 may emerge to indicate that a sealshould be replaced.

Mounted atop the cylinder 24 is an oil motor 118 having a driven shaft119 to which is fixed the previously mentioned sprocket 117. Thesprocket chain 49 as above stated is trained about the sprocket 47 andabout the sprocket 117 so that the motor 118 turns the peel carrier 34.Flexible oil connections 125 extend to the oil motor.

The peel 75 has tongs comprising a mounting member 120 connectedtherewith at 121. Pivoted to the mounting member 120 of the tongs at 122are jaws 123 each in the form of a bell crank lever having one armextending inwardly and having a pivot and slot connection 124 with therod 60.

The tongs might be mounted directly against flange 42 without theinterposition of the member 75 which has been referred to as the peelproper but which in the structure shown in the drawings constitutes aspacer tube which may be lengthened, shortened or dispensed with. Thelength of the tube and of the rod 60 will, in any case, be determined tosuit the particular operation for which the manipulator is furnished.

The portion of my manipulator structure shown in Figure 6 isunprecedentedly short-coupled and hence adapted for utilization in alift truck manipulator. At the same time it is very strong and ruggedand operates in a simple manner and is not likely to become out oforder. Although such structure is exceptionally well adapted toemployment in a lift truck manipulator it may also be used in othermanipulators with advantages in economy of construction, strength,foolproofness and simplicity of operation.

Moreover. the portion of my manipulator structure shown in Figure 6 isunprecedently short-coupled for a mechanism which is intended to notmerely operate the tongs at the end of the peel but also have a rotatingaction. Peel mechanisms have heretofore been proposed for charging workinto and withdrawing the same from furnaces and the like which have beenprovided with tongs and means for operating the tongs but not with meansfor peel rotation. In such cases either the cylinders for operating thetongs have been mounted outside the peel structure or, if they have beenwithin the peel structure on the peel axis, no provision has been madefor rotatable connections for the admission of fluid under pressure atopposite sides of the piston. My structure as herein disclosed does awaywith all swivel connections, bulky piping and excessive axial length.

Figure 7 shows a resilient connection between the crosshead and thepiston rod 94. The members of. the crosshead are connected, as bywelding, with a washershaped member 128 which is therefore in eflect aunitary part of the crosshead. The member 128 has therethrough a centralbore 129. The piston rod 94 has an extremity 130 of reduced diametermaking a shoulder 131 with the body of the piston rod. Seated on theshoulder 131 is a washer 132 having a central bore 133. The reducedextremity 130 of the piston rod passes through the bore 133 of thewasher 132 and also through a bore 134 of a generally cylindrical blockof rubber or other resilient material 135 and thence through the bore129 of the member 128, after which a washer 136 and a nut 137 areapplied to the extremity 130 as shown in Figure 7. Some of the shockimparted to the peel in the use of the manipulator may be absorbed bythe resilient block 135. Normally the block may be under moderatecompression between the washer 132 and the member 128 but when the peelis subjected to downward force the member 128 may move downwardlyrelatively to the piston rod 94 and further compress the block 135. Sucha condition is illustrated in Figure 7 in which substantial clearance isshown between the bottom of the washer 136 and the top of the member128. While normally the block 135 would not take the place of theresilient structure including the springs 108 and 114, it may be used inconjunction therewith or when the shocks to which the peel is subjectedin use of the manipulator are of minor magnitude the block 135 may beused to replace the structure including the springs 108 and 114.

Figure 8 shows a resilient connection between the crosshead and thepeel. Connected with the plate .16. which constitutes the web of thecross member 96, by bolts 138 is a plate 139 having integral therewithan eye 140 and strengthening flanges 141. The pivot pin 91 passesthrough the eye 140. Disposed between the plate 16 and the plate 139 isa mass of resilient material such as rubber 142. Normally the mass ofresilient material 142 is maintained under moderate compression but itis subject to increased compression at any portion thereof due to shocksimparted to the pee] in use of the manipulator. This feature may be usedin combination with the structure including the springs 108 and 114 orin combination with other of the resilient connections herein disclosedto distribute the shocks imparted to the peel in use of the manipulator.

Figures 9 and 10 show a resilient connection between the guideway forthe crosshead and the means for moving the guideway about its pivotalconnection with the truck. The guideway is constituted by the frame 19which has connected therewith at each side edge by bolts 143 a strap 144and a plate 145. Turnably mounted within each strap is a block 146having trunnions 147 and 148 rotatably mounted in the correspondingplate 145 and strap 144 respectively as shown in Figure 10. Each block146 has therethrough a bore 149 through which the corresponding pistonrod 85 passes. A compression coil spring 150 is biased between eachblock 146 and a collar 151 fastened to the corresponding piston rod 85to the left of the block viewing Figure 9. A compression coil spring 152is biased between each block 146 and a collar 153 fastened to thecorresponding piston rod 85 to the right of the block viewing Figure 9.Thus the frame 19 is resiliently mounted for movement about the axis ofthe front axle 5 due to shocks imparted to the peel in use of themanipulator. This feature may be used separately or in combination withone or more of the other resilient features above described.

Thus I provide a lift truck manipulator which fully overcomes thedisadvantages of prior manipulators and provides for the handling ofheavy hot masses with a maximum of efficiency while maintaining theover-all length of the manipulator at a minimum. At the same time thetruck is protected from the severe shocks imparted to the peel when thework is being operated upon. The lift truck manipulator is compact andrugged and requires little maintenance.

The structure shown in Figure 6 is not claimed in detail in thisapplication but is claimed in my copending application Serial No.320,287, filed November 13, 1952. Other subject matter shown but notclaimed herein is claimed in my divisional applications Serial No.470,625, filed November 23, 1954, and Serial No. 633,101, filed January8, 1957.

While I have shown and described certain present preferred embodimentsof the invention it is to be distinctly understood that the invention isnot limited thereto but may be otherwise variously embodied within thescope of the following claims.

I claim:

1. A truck-mounted material handling device comprising a self-propelledwheeled truck of the type used for lifting and transporting articleswhich has a generally upright guideway, a crosshead guided by theguideway, means for moving the crosshead to selected positions in theguideway, a load-carrying arm pivotally carried by the crosshead andresilient means acting between the arm and the crosshead maintaining thearm in approximately predetermined orientation but permitting pivotalmovement of the arm relatively to the crosshead when shocks are impartedto the arm.

2. A truck-mounted material handling device comprising a self-propelledwheeled truck of the type used for lifting and transporting articles, agenerally upright guideway carried by the truck, a generally verticallyelongated crosshead guided by the guideway, means for moving thecrosshead to selected positions in the guideway, a loadcarrying armpivotally carried by the crosshead at the lower portion of the crossheadand projecting generally horizontally from the crosshead and resilientmeans extending from the upper portion of the crosshead to a portion ofthe arm substantially spaced from the crosshead maintaining the arm inapproximately predetermined angular position relatively to thehorizontal but permitting pivotal movement of the arm relatively to thecrosshead when shocks are imparted to the arm.

3. A truck-mounted material handling device comprising a self-propelledwheeled truck of the type used for lifting and transporting articles, agenerally upright guideway carried by the truck, a generally verticallyelongated crosshead guided by the guideway, means for moving thecrosshead to selected positions in the guideway, a loadcarrying armpivotally carried by the crosshead at the lower portion of the crossheadand projecting generally horizontally from the crosshead, a yoke havingits cross element connected with the arm at a portion of the armsubstantially spaced from the crosshead and having its side elementsextending generally upwardly and toward the upper portion of thecrosshead and resilient connections between the side elements and theupper portion of the crosshead whereby the arm is maintained inapproximately predetermined angular position relatively to thehorizontal while pivotal movement of the arm rela tively to thecrosshead is permitted when shocks are imparted to the arm.

4. A truck-mounted material handling device comprising a self-propelledWheeled truck of the type used for lifting and transporting articles, agenerally upright guideway carried by the truck, a generally verticallyelongated crosshead guided by the guideway, means for moving thecrosshead to selected positions in the guideway, a loadcarrying armpivotally carried by the crosshead at the lower portion of the crossheadand projecting generally horizontally from the crosshead, a yoke havingits cross element connected with the arm at a portion of the armsubstantially spaced from the crosshead and having its side elementsextending generally upwardly and toward the upper portion of thecrosshead, a cross member through which the side elements of the yokepass, spring means pressing generally downwardly on the cross member andgenerally upwardly on the side elements of the yoke, a rod pivotallyconnected with the upper portion of the crosshead and passing throughthe cross member and spring means pressing generally downwardly on thecross member and generally upwardly on the rod whereby the arm ismaintained in approximately predetermined angular position relatively tothe horizontal while pivotal movement of the arm relatively to thecrosshead is permitted when shocks are imparted to the arm.

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